A 54 year old gentleman with altered bowel habits

A 54 year old gentleman presented to my clinic with a chief concern of altered bowel habits since 12 years.

A principled and inquisitive man, he reports first having altered bowel habits nearly 14 years ago, manifested by an increase in time spent in the loo for complete evacuation. On pressing further, he says that his visit to the wash is often preceded by a vague pain in his abdomen, which apparently may or may not relieve with defecation. He describes the pain as a poorly localising, diffuse, spasmodic pain that can last from anywhere between 5 to 15 minutes.

This pain, he says, is often precipitated by hunger and almost always alleviates with food intake. On probing further, he says he has lost a significant amount of weight over the past 14 years but his weight loss has now stabilized and has remained at 57 kg for a decade now. 

Description of his excursions in the toilet provide further detail - over the past 10 years, his visits have increased in frequency per day (from 1 to 2 -3 per day), he has had to strain even more, which is often accompanied by the pain described above. He also reports that the stool consistency is frequently watery, and often associated with a mucus discharge. On occasions, he has admitted to having seen undigested food, such as pieces of carrot and coriander. He says that he was perplexed and shocked on seeing these. At this moment, his wife reports that his stools are sometimes difficult to flush, stain the commode easily and intensely and have an unbearable stench. He also reports that he occasionally feels a sense of incomplete evacuation and has to strain further or sit longer to get a sense of complete evacuation. He cannot recall ever having seen dark colored or greasy stools. He also reports flatulence and a feeling of bloating and nausea, particularly on consuming wheat. Avoiding wheat only brings partial relief of these symptoms.

He also reports that on some occasions, he saw red blood streaked on his stools and that he felt some small palpable nodules while washing.

He reports having a good appetite with an intact craving for foods, which he has had since childhood. He also says that he has a mild difficulty in swallowing, in that he often finishes his meal much later than his peers and often has to chew for longer. He however, does not report ever having drooling of saliva, or food regurgitating from his mouth or nose. He also does not report having to turn his head and neck sideways to facilitate swallowing. He does not report food impaction, hoarse voice, or any otological symptoms. He however reports a debilitating reflux, which causes heartburn and troublesome belching. He does not report excessive salivation or lacrimation.

These symptoms have plagued him for more than a decade now and have culminated in several visits to hospitals and super specialist consultations. He has been subjected to a battery of tests over these years, including multiple upper GI endoscopies and lower GI endoscopies. He was biopsied twice for a provisional diagnosis of Crohn disease and both times the biopsy returned negative.

Review of systems is significant for occasional visual blurring (he has myopic vision requiring spectacle use) and dry nose which requires nasal drops use. He has no history of pedal edema or facial puffiness, frothy urine, blood mixed with stool, jaundice, malaena, worms per rectum or clay colored stools. He also denies any history of joint pains, dyspnea, chest pain, skin hyperpigmentation, generalized itching or constipation.

Past Medical History

The patient's past history is significant for childhood asthma and frequent hay fevers. He also reports having taken a Mantoux test (reasons unknown), for which he tested positive and took Rifampicin 600mg for 6 months in1998. Over the past decade or so, he was subjected to several blood tests. A common theme he says, that emerged from these blood tests was 'low Vitamin B12 and low Vitamin D levels'. He says he was treated with vitamin supplements for the same for a few years now. 

He reports taking PPIs, antibiotics and multiple other supplements recurrently over the past decade. He has taken all his vaccines and is double vaccinated for COVID-19. He recently had mildly symptomatic COVID-19, from which he recovered in 5 days.

Personal History

The patient is a fit and active 55 year old man. He enjoys long analytical discussions, long walks, reading and spending time alone and occasionally with his family. He lives with his wife and his daughter, who is currently away from home for higher education. He lives in Navi Mumbai and has had to move homes frequently due to promotions at work. He has lived in Gujarat, Panjim, Visakhapatnam, Vijayawada, Guntur, Cochin, Bengaluru and Mumbai. He also frequently visits Hyderabad to see his family.

The patient is a pure vegetarian and enjoys a good south Indian meal. He enjoys eating sweets and has a wide culinary liking. He reports that his sleep is often disturbed, having to wake up in the middle of the night, often in the second half of the night to pass stool. He reports that the stool he passes then, is often watery and foul smelling. Otherwise, he often reports awakening at night at around 2:30 AM for no apparent reason and has to struggle to get himself back to sleep again for a few hours. He reports waking up groggy at around 6:30 am, when he usually takes a morning walk.

He does not report having any addictions or indulgences. His bladder habits are normal. His libido is intact. He does not have hypertension, diabetes or any other chronic illnesses. He was treated for presumptive TB in 1998 with Rifampicin monotherapy.

 

Problem Representation 

A 55 year old man presented with a 12 year history of altered bowel habits, suggestive of chronic malabsorption and maldigestion. He has required multiple medical consultations for his problems. However, a conclusive final diagnosis has remained elusive.

Case Analysis

 55/M with chronic history of mucus in stool, pain before defecation, difficult to flush and foul smelling stools with undigested food, likely has malabsorption. He also reports belching and reflux which could suggest maldigestion. Nocturnal diarrhea is strongly suggestive of inflammatory diarrhea. Could also be a feature of malabsorption.

Functional problem - Malabsorption.

Anatomical lesion - The patient has reported a long history of low vitamin B12 levels with a borderline anemia (10 - 11 g%). He has not reported ever having iron deficiency, which suggests that iron absorption and thus iron cycle could be functionally intact. Thus, the lesion being in the proximal duodenum (D1 & D2) is unlikely, by which iron cycle is completed. 

He has not reported clay colored stools or features of obstructive jaundice, suggesting that this enterohepatic circulation is intact. This means that from the synthesis of bile from the hepatocytes, to their excretion into the biliary radicles, to their outward flow into the bile ducts into the hepatic ducts and the common bile duct is intact, This also means that there is likely no obstruction of flow of bile via the ampulla of Vater into the duodenum (D2). This could also likely mean that the synthesis of primary and secondary bile acids is intact - which happens at the terminal ileum and colonic bacteria (which are also required to convert disaccharides to short chain fatty acids [SCFAs]).

The patient has also never developed features of hypoproteinemia, such as facial puffiness, pedal edema or abdominal distension (hypoalbuminemia). He also has not shown an increased propensity for susceptibility to infections (hypogammaglobulinemia). Thus, the patient possibly does not have fat, bile acid or protein malabsorption.

Features of bulky, intensely foul smelling mucus stools could suggest isolated carbohydrate malabsorption. He also reported seeing undigested food particles in his stools, which likely suggests maldigestion.

Although poorly sensitive towards clinical implications, low levels of Vitamin B12 indicate poor absorption. The fact that these levels have improved with oral supplementation suggests that endocytosis of B12 (cyanacobalamin) upto the level of terminal ileum is intact (this means that haptocorrin synthesis and function, IF synthesis and function and cubulin synthesis are intact). This could suggest a possible terminal ileal pathology, with even overgrowth of bacteria a culpable factor (competing for B12).

Thus, it appears that the anatomical lesion is likely in the small bowel, particularly in the jejunum and ileum.

Pathophysiology - Nocturnal diarrhea has been shown to be a feature of inflammation. However this is also seen in Diabetic Enteropathy and also in Small Intestinal Bacterial Overgrowth and other parasitic infections of the gut. Inflammation of the small bowel is the most likely culprit.

Etiological Agent - Can be due to the following agents

1. Giardiasis
2. Tropical sprue / Celiac disease
   
3.  Small intestinal bacterial overgrowth (SIBO)
   
4. Amoebiasis
5. Inflammatory bowel disease (IBD) - Crohn disease
   
6. Whipple disease
7. Autoimmune enteropathy
8. Microscopic colitis
9. Eosinophilic oesophagitis
10. GERD
    

Clinical Exam 

Vitals - PR - 86 bpm; Temperature - Afebrile; RR - 16/min; BP - 110/70 mm Hg

Both general and systemic examination are essentially normal.

Investigations required

• Complete blood picture with peripheral smear. 
• Stool for ova, eggs and cysts. Stool leucocyte count.
  
• Upper GI endoscopy with duodenal biopsy for Giardiasis, Amoebiasis, Celiac sprue, Crohn disease and autoimmune enteropathy
• Hydrogen breath test for SIBO
• Duodenal or jejunal biopsy (ideal) for Whipple disease
• CT Enteroscopy, if pathology not apparent on above tests.