Hirschsprung's disease: This condition is characterized by the absence of ganglion cells in the distal bowel, leading to a functional obstruction. The sticky feces could be due to the buildup of fecal matter behind the obstruction, which then becomes desiccated and sticky.

Hypothyroidism: Hypothyroidism can cause constipation due to decreased gut motility. The sticky nature of the feces might be related to the altered gut environment and potential for increased water absorption.
Celiac disease: This autoimmune disorder can lead to malabsorption, including altered fat absorption, which might result in sticky, greasy stools.
Gastroesophageal reflux disease (GERD) and dysphagia: Though more commonly associated with esophageal symptoms, severe cases can lead to altered eating habits and subsequently to constipation. The sticky nature could be from altered food intake or secondary to medications used for treatment.

Intestinal obstruction: Any cause of mechanical obstruction (e.g., tumor, adhesions, volvulus) could lead to constipation. The sticky feces might be a sign of partial obstruction with altered fecal consistency.
Neurological disorders (e.g., Parkinson's disease, spinal cord injuries): These conditions can affect bowel motility, leading to constipation. The sticky nature of the feces could be due to prolonged retention and desiccation.

Chagas disease: Caused by Trypanosoma cruzi, this infection can lead to the destruction of the myenteric plexus of the gut, resulting in megacolon and constipation. The feces might become sticky due to chronic constipation.
Amyloidosis: The deposition of amyloid proteins in the gut can disrupt its function, potentially leading to constipation and altered stool consistency.
Familial dysautonomia (Riley-Day syndrome): A rare genetic disorder affecting the development of the autonomic nervous system, which can lead to gastrointestinal dysmotility and constipation.